.progress {
    border: 1px solid #fff;
    min-width: 50px;
    height: 18px;
    line-height: 18px;
    color: #fff;
    text-align: center;
    position: relative;
    font-size: 12px;
    .pb-bar {
        display: block;
        width: 0;
        height: 100%;
        background: #999;
        opacity: 0.6;
    }
    .progress-content {
        position: absolute;
        left: 0; 
        right: 0;
        top: 0;
        bottom: 0;
    }
}